Zixin Liu and  Shu Lü and  Shouming Zhong and  Mao Ye,  Exponential Stability and Periodicity of a Class of Cellular Neural Networks with Time-Varying Delays.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    March 2009, vol. 27(3). 223 - 230
    [viewed 23 January 2020]. Available from: https://publications.waset.org/pdf/860.